Page 9 of the Wine Society catalogue, November 1918, entitled [color=#009900]‟DON’TS,” for Wine Drinkers.[/color] wrote:1. DON’T put ice into Champagne or sparking wines. It spoils bouquet and flavour.
2. DON’T serve Champagne or Sparking Wines too cold.
3. DON’T warm Clarets or Burgundies by the fire.
4. DON’T keep wine stored on high shelves, as heat ascends.
5. DON’T serve or decant old wines soon after arrival. Keep them in cellar for some time.
6. DON’T let stock run low. Newly arrived wines must have time to settle.
7. DON’T be frightened when you see floating particles in White Wines ; it is evidence of purity.
8. DON’T stand Champagne up ; flatness is sure to result.
9. DON’T leave wines in their cases or covers, but unpack and bin at once. Full bottles sometimes get overlooked, and find their way back to the wine merchant.
10. DON’T keep your jars and cases, but return to cellars promptly.

From Harrods Food News, 18th July 1927, and reproduced by permission of the Company Archives, Harrods Limited.
Harrods Food News was a weekly publication run during much of the inter-war period, a sampling of which suggested that it never listed vintage port.